code: def get_available_backends():
      """
      Get all available audio_utils' backend modules.
  
      Returns:
          list of str
      """
  
      return backend_manager.get_available_backends()
  
file_path: nnabla/python/src/nnabla/utils/audio_utils/__init__.py
imports: from __future__ import absolute_import
  import numpy
  from .backend_manager import backend_manager
  from .common import rescale_intensity, _auto_scale_before
label_desc: Use image node_id 3 for calling a global function with example usage: get_available_backends() and returns: backend_manager